Seal ring for conical cutters



Oct. 25, 1932. H. 'r. B GETT E AL 1,884,965

SEAL RING FOR CONICAL CUTTERS Filed on. 19. 1931 2g 2Q I 24 an I W M FIG. 3

25 HENRY T. BAGGETT Br LEWIS 5.6ARFIELD INVENTORS ATTORNEY BY 6?. mm

Patented Ot. 1932 UNITED STATES.

PATENT OFFICE HENRY '1. B AGGETT AND LEWIS E. GARFIELD, OF HOUSTON, TEXAS, ASSIGNOES TO HUGHES TOOL COMPANY, OF HOUSTON, TEXAS, A CORPORATION OF TEXAS sen. RING roacourcu. cu'r'rnns Application filed October 19, 1931.

Our invention relates to cutters for well drills and more particularly to the lubrication thereof.

The cutters on deep well drills operate at the bottom of well bores that are frequently about a mile deep. They roll on bearings that must withstand heav loads and operate in an atmos here of mu and grit which is under a statlc head of liquid averagingover a thousand pounds to the square inch. The lubricant is usually fed to the bearings through lubricant passages through the drill head and the cutter shafts from a reservoir connected with the said head. 7

Due to the high static fiuidpressure of the liquid in the hole outside the cutters, it is found that mud will force itself around the bearings of the cutters and the abrasive ma- I terial carried by the mud will cause rapid wear of the bearing surfaces of the cutters and their bushings so that they will not last.

until the teeth upon the cutters are worn out.

We desire to prevent the entrance of mud to the bearings of cutters of the character described and to hold the lubricant on the bearings so that the usual excessive bearing wear will be avoided.

. We have as an object to provide a seal rin to be-used on the cutter which will seal 0 the entrance of the mud about the bearings of the cutter.

We also contemplate the use of a sealing means on the washer which is adapted to bear against the cutter and keep out slush from the cutter hearings in use.

In the drawing, Fi 1 is a side viewof a portion of a drill hea with a cutter thereon equip d with the invention, the cutter and shaft eing in central vertical section.

Fi 2 is a broken sectionalidetail ofthe packing on the cutter. Fig. 3 is 'a similar view of the seal ring onthe washer.

In Fig. 1 the lower end of drill head is indicated at 4. The cutter shaft 5 is formed integral therewith and lubricant ma reach the end of the shaft to lubricate the aring through a channel 6 in the usual manner well known in the art.

The shaft 5 is threaded at 7 to engagewith the bushing 8 which is frusto-conical in shape Serial No. 568,709.

and surrounds the end of the shaft. The forward end of the shaft is reduced in diameterbut is unthreaded, forming a support for the end of the bushin The bushing 8 is ormed with a reduced neck 9 thereon and the cutter 10 is constructed with an inner recem to receive the bushing; and a retaining ring 11 is screwedwithin the base of the cutter engagin about the neck 9 to hold the cutter rotatab y upon the bushing. The cutter is toothed on its outer surface in the usual manner.

When the cutter is mounted for operation uponthe shaft as shown, the lubricant will pass from the channel 6 in the bit head through the shaft 5 and through an opening 12 in the bushing to the bearings. The usual difliculty is that the fluid pressure in the hole outside'the cutter is so great that the mud will force the lubricantback toward the lubricator and the mud will enter about the bearing surfaces at the base of the cutter and prevent the access of the lubricant to the hearings to a serious de ree.

We place a seal ring in an annular recess 13 formed in the retaining ring and bushin As seen in Fig. 2 this ring A is, in fact, ma e up of three parts; an inner washer 14 which is preferably made of leather or similar flexible tough, material. There is also an outer ring 15 of metal such as steel. This ring has an inwardly turned flange 16 at its outer margin to bear a ainst the outer edge of the washer 14 and orce it into a countersunk groove 18 and thus hold it clamped in position. Between the rings 14 and 15 is a ring 17 of rubber or like compressible material which is referably corrugated circumferen tially on its upper surface so that it may be compressed in thickness and thus serve to better form a seal.

en the seal device A is placed in assembled position in the recess 13 the margin of the recess in the retaining ring is upset at 19 about the steel ring 15 to force the said ring 15 into tight clamping engagement with the two inner rings and to serve also to hold them in place. This upsetting of the material of the retaining ring 11 may be done by spinwhic nin of the metal or by the use of a hammer as esired.

. This type of seal ring has been found to be particularly effective in preservintgha seal at the bearings. The ring rotates wi ter and we find that the pressure of liquid from the outside tends to preserve the seal and leakage is substantially prevented.

The washer also may be provided with a packing means still further assisting in preventing access of mud to the bearings. The washer 20 is formed with a recess 21 s aced from the shaft 5 and opposite the line 0 division between the bushing and cutter. In Fig. 3, it will be seen that this recess is deepest at 23 to receive the rubber washer 24. The outer washer 25 is of leather or similar material and is wider than the ring 24. One margin of the leather ring 25 is forced into a roove 26 .b the pressure of a shim or was er 27 fits against the seal tin and the washer 20 opposite the neck 9 of t e bushing.

In Fig. 3 it will be noted that the packing in the washer is shown without the use also of the ring A in the cone. When the seal ring in the washer is de nded upon to prevent access of mud to t 'e cone bearings or to avoid loss of lubricant, the cone bears strongly against the seal ring and compresses it within the washer. Thus leakage along the bearing surface is largely avoided. When the two sets of packing are used in combination a particularly effective seal is provided.

It will thus be possible to prevent the'usual wear of abrasive material upon the bushing and make it ossible for the cutter to 0 rate until its cuttm surface is destroyed without ap reciable di culty with bushing wear. at we claim as new is:

1. In combination, a head, a shaft integral therewith, a bushing on said shaft, a cutter surrounding the end of said shaft, a washer between said cutter and said head, a seal ring partly in said cutter and partly in said bushin and a com ressible packing memberpositioned in sai washer and adjacent said seal ring.

v 2. A drill head, a shaft thereon, a bearing surface associated with said shaft, a cutter surrounding the end of said shaft and a seal ring fitted within a recess between said bearing surface and said cutter, one edge of'said recess being upset to clamp said ring in position.

3. A drill head, a shaft thereon, a bushing surroundin the end of said shaft, a cutter on said bus 'ng, a retaining ring on said outter, a seal ring fitted within a recess formed partly in said retaining ring and partly in.

said bushing, said seal ring mcludin a flexi ble washer, a clampingring of meta and an intermediate ring of compressible material.

4. A bushing, a cutter rotatable thereon, a recess formed partly in said cutter and partly insaidbuahingasealringinsaidrecess,

.the out including an irmer washer of flexible material, a ring of rubber and a ring of rigid material clamping said rubber ring upon said washer. e

5. Abushing, a cutter rotatable thereon, a recess formed partly in said cutter and partly in said bushing, a seal ring in said recess, including an inner washer of flexible material, a ring of rubber and a ring of rigid material clamping said rubber ring upon said washer, said rigid ring having an inwardly directed flange engaging said washer.

6. A bushing, a cutter rotatable thereon, a recess formed partly in said cutter and partly in said bushing, a seal ring in said recess, including an inner washer of flexible material, a ring of rubber and a ring of rigid material clamping said rubber rlng upon said washer, means upon said rigid ring clampingly engaged with said washer and means on said cutter holding said rigid ring in position.

7. A drill head, a shaft thereon, a bushing on said shaft, a cutter rotatable on said bushing, awasher between said head and said outter, a packing ring set in.a recess in said washer adjacent the end of said cutter and bushing, and resilient means to hold said packingring against said cutter.

In testimony whereof, we hereunto afiix our signatures this the 14th day of October,

LEWIS E. GARFIELD. HENRY 'r. BAGGETT. 

